F15Rules

On 18/08/2023 at 22:12, Louis D said:

It helps if you can wedge your butt up against a wall to steady your whole body while doing this, or use a sitting position.

The mind boggles!! 😂😂

Dave

ED Refractor.

The End.

Dave

I've owned the MK66, great scope.

If you can find one, I would recommend the Vixen Super Polaris mount..why? because the engineering is great, and because you can use the SP mount in both Altazimuth and Equatorial modes.

A Vixen GP (Great Polaris) has a higher weight capacity, but can only be used in Equatorial mode.

Although the MK66/67 scopes are solid, they are also short, so either of the above mounts should take them very easily.

Hope that helps,

Dave

I reckon it's been nigh on 10 weeks since my last observing session. My FS128, "Trinity",  has been in her Oklop holdall in our cool dining room for the past 5 weeks or so, due to the number of Thripps, Thunderflies etc.

Like many SGLers, I've found this summer to be a very depressing time, astro-wise, following on from the dreariest Spring I can remember since 2007.

All the above said, it may explain why I have felt that I've had a real tonic in the past few days..

Firstly, on Saturday night, my wife and I attended a talk on the Perseid meteor shower hosted by East Lincolnshire Astronomy Club, in Scamblesby village hall in the middle of the Lincolnshire Wolds. It was run in partnership with the Lincolnshire body who have promoted the Lincolnshire Area of Outstanding Natural Beauty (AONB) for the past 50 years since the area's designation as an AONB.

After the talk we went to the nearby Red Hill nature reserve observing site (Bortle 4), with the aim of observing some Perseid meteors and other celestial objects. The sky did have some gaps in the clouds and we did get to see some cracking meteors, before the holes closed up at c 11pm. We also got the chance to see a few nice scopes up close, including a Tele Vue 102 and a huge 20" Dobsonian. Sadly, the skies prevented any proper viewing, but the ELAC club members are to be congratulated for welcoming some 20+ strangers to their talk and subsequent observing site..and, best of all, my lovely wife came with me and enjoyed herself!🤗

Secondly, last night (Tuesday) was by far the best night for literally months in my home location at the bottom end of the Wolds.. I got out my vintage Vixen 80mm F15 achromat to check out a few favourite summer doubles..

This scope just takes me back to my youth..long, thin tube but just looks so cool..this one has a 2" retrofitted focuser, and I put in my decloaked huge Celestron Axiom 31mm to look at Albireo..this scope will never be a widefield scope, but honestly, the field presented by this combination, with Albireo centred, was jaw dropping, with great colour rendition and negligible CA.

Using my Pentax XL zoom I moved through the magnifications up to 8mm, giving 150x in this scope.. perfect bullseyes, with a steady, single diffraction ring around each component. Beautiful!

After fully half an hour just gazing at Albireo and it's Milky Way background, I moved to Delta Cygni, a wonderful, (and not easy at 80mm aperture) close double at c 2.4" of arc. At 150x, I glimpsed the faint companion sitting right on the diffraction ring, and the scope took up to 260x with a 2.25x barlow, still delivering a clear image.

The only other objects I looked at were Vega and Epsilon Lyrae (the double double) and a nice view of Saturn, which was lowish down to the south east.

Exhilarated, and mojo recharged, I packed up at c 12.20am after 90 minutes or so of pure bliss.

Roll on the autumn and winter skies!!👍

Dave

3 hours ago, JeremyS said:

https://arxiv.org/abs/2308.06396
 

Is the above available in English, Jeremy?🥴

Dave

Q. What is your favourite f ratio ?

A. I'm not telling. Just don't look at my SGL handle..🙃

Dave

John, 

Write out 100 times..

"Been there, done that, got the T shirt, been there, done that, got the T shirt.."

Dave 😁

12 minutes ago, NGC 1502 said:

On 28/07/2023 at 11:44, Sunshine said:

but I guess you have no issue with such a large refrigerator on your DX? I can’t imagine my GP handling such a scope.                
 

 

                                  Epic predictive text strikes again 😁😁😁

Great stuff Ed!

I bet such a contraption would look really cool though..

On 28/07/2023 at 13:05, dweller25 said:

I found that replacing the stock focuser with a Feathertouch reduced focus jiggles even more.

...or add Takahashi's own MEF3 1:7 microfocuser at much lower cost..😊

https://www.firstlightoptics.com/takahashi-other-accessories/tak_tka00733.html#:~:text=About this product&text=Takahashi MEF 3 is a,180 and E-130D telescopes.

I bought mine several years ago used in mint condition for £150 and am very pleased with it's performance. It also enabled me to retain the excellent original Tak 2.7" focuser which is very robust and can take heavy eyepieces such as my Axiom LX 23mm and 31mm.

Here's a link to a thread I found helpful when installing my MEF-3 microfocuser, including a useful visual aid

Dave

I've used Trinity several times on a GP-DX and it worked well, with one caveat: you do need a solid tripod under the GP-DX, and IMHO a standard EQ5 steel tube tripod isn't up to the job.

A good wooden tripod such as a Berlebach would dampen vibrations far better. My own is a solid custom made fixed height wooden one with a Berlebach spreader and is very solid👍

Dave

35 minutes ago, MalcolmM said:

Does anyone know if the outer 50% of the FOV is likely to be similar/better/worse than the Abbes or LEs?

Malcolm 

Well, based on my own Tak Abbe 12.5mm orthos, I can't see how the outer 50% of the FOV could be any better to my eyes..

Ok, so I'm using them at F8, in a Tak scope..maybe a faster scope, say F5, would show something different, but for my scope they show me the best view optically that I can detect, within the limitations of their designed FOV.😉.

Dave

Roy is correct.

And he is also correct that a (heavy duty) dovetail can be drilled to allow the clamshell to be fitted to it..but unless you have a Tak mount with 35mm spaced threaded holes to receive the clamshell, yod need to have some kind of adapter made.

If you have a different mount head that will accept standard Vixen style dovetails, then you could simply buy (or drill) a Vixen ADM type dovetail with 35mm pre-drilled holes (or drill them yourself) and then bolt the dovetail onto your clamshell from underneath..the dovetail would need 2 strong clamps: you could then clamp the dovetail/clamshell assembly to your mount.

I hope this makes sense?

The photos below show my Tak mount head with 35mm spaced holes as supplied. Also the clamshell close up and open when attached to my Tak mount, and finally a custom solid aluminium bar dovetail which I drilled with 35 mm spaced holes: this was however to allow use of other scopes on my Tak mount, whereas you may want to secure your Tak FS128 scope to a non Tak mount..

It shouldn't be too difficult to achieve though and I hope the photos help you visualize what I mean😊.

Dave

5 hours ago, UKDiver said:

I have the impression that Takahashi have designed a coherent system. If you wish to use something outside of that system, why should they take account of all the possible combinations?

I do use other kit on mine. My choice and I must bear the consequences with adapters and hassle.

I wonder if all Takahashi's own branded eyepieces all come to focus with their scopes? If not, that would be a bit naughty...

If they will, fair enough..most of us use a plethora of various brands and types, so it's not surprising if some of those don't come to perfect focus in a Tak focuser that almost certainly was designed only with Takahashi branded eyepieces in mind.

I confess that when I acquired my FS128, one of the first things I did was to replace the original back end focuser adapters.

This was initially as I wanted to use 2" eyepieces, and the original FS128 back end focuser was set up for 1.25" eyepieces only, and a genuine Tak 2" adapter for the Tak focuser was very expensive.

So it was Baader to the rescue, and I used a combination of their Tak specific adapters to allow me to bring all my 2" and 1.25" eyepieces to focus, and also to get native focus in binoviewers for most of my then 1.25" binoviewing eyepiece pairs.

Since then I have also switched to Baader 1.25" prism diagonals, which use up less of the optical path. 

Nicola, I hope you manage to sort out the focusing on your own Tak. Once you have, I know you will enjoy the superb views presented by your scope, knowing that the optics in your scope match or beat most other scopes commercially available today..😊

Dave

Lovely report, thanks for sharing..😊👍.

Your observing pleasure will greatly increase when you can mount your bins, ideally with a trigger grip, but pretty much any kind of tripod and mount will transform what you can see.

Here are some photos of one of my favourite pairs of bins, my old but pristine (1980s I believe) Vixen B4 Japan series porro prisms..they are only 7x50s, but very heavy, and they really do work at their best when supported properly.

They have a 7.3 degree field, are waterproof (probably water resistant would be more accurate!) and have individual focusing for each eye, rather than centre focusing for both eyes.

This latter feature is good for astro viewing, but is not easy to do for each eye whilst they are hand held..a tripod makes this much easier.

The tripod shown below was bought new by me c 10 years ago on Amazon, and was branded Ravelli at that time, although later versions were renamed "Amazon Essentials"..

https://www.amazon.co.uk/AmazonBasics-177-cm-Pistol-Grip-Tripod/dp/B01LQX0P8Q

Unfortunately not available at the moment..

The above image does not do the bins justice (my old smartphone camera lens has a crack across it!), but trust me, stars are pinpoint cross the field and contrast and sharpness are  both excellent..

When supported by a tripod your bins will show you a lot of wonderful sights..enjoy!

Dave

Cyclops:

2 x Pentax including 1 zoom

2 x Axiom LX UWA

1 x Baader Zoom Barlow 2.25x (also used for binoviewing

1 x W.O. 1.6x Barlow (also used for binoviewing)

Binoviewing :

Tak Abbe Ortho 12.5mm pair

W.O. 20mm wide angle pair

Meade Series 4000 32mm pair

Dave

Oh, and I forgot to mention the Baader 1.7x GPC which I bought with my Maxbrights but haven't actually used as yet..

On 20/07/2023 at 19:04, Peter Drew said:

Never counted them but must be in three figures.    🙂

Peter, the question was how many eyepieces, not how many scopes!!🙂🙃 

Dave

3 hours ago, Saganite said:

They're not Malcolm, I am only 4' and 8 stone...

Oh...have you put weight on since then, Steve??😁😁

Dave

On 03/07/2023 at 20:10, MalcolmM said:

The big advantage of the Tak cradle from my point of view is the ease with which you can loosen the clamp a bit and slide the scope so easily to achieve balance...

Agree with this 100% Malcolm. I actually used to use a Tak clamshell originally from an FS102 on my then Vixen ED103s..both scopes had oversized 114mm tubes, so the clamshell fitted properly. 

It made the Vixen feel totally secure..

Above: my Vixen ED103s sporting the FS102 Tak Clamshell, fitted perfectly 👍.

I think there's also another angle to this seeming "Takahashi obstinacy" in persisting with clamshells, and it's to do with their innate attention to excellence..

I believe that in the Takahashi  corporate mindset, they want to build and sell  the most complete and "total" package they can: so, in their minds, their perfect customer buys not just their scope OTA, but also the mount - which means a Tak mount, normally a driven Equatorial.

Now, Taks own mounts are built to accept a Tak clamshell via twin (M10, I think) hex bolts, whereby the bolts pass through the base of the clamshell, directly into the mount itself, and are tightened to ensure total security of the tube, in its clamshell, immovably fixed into the Tak mount (I have this very arrangement with my FS128 and Tak EM2s equatorial).

The worst thing that can happen with the above setup is that if you loosen the clamshell to rotate the ota or move it up or down for balancing, it could allow the tube to slide a bit..but the clamshell would not detach from the mount so your OTA couldn't fall onto the ground.

So, while the Takahashi "attachment" (sorry😁) to their clamshell system may irritate some, I actually applaud it as proof of their continuing dedication to "system excellence"..

My good astro friend Steve (@saganite ) holding my FS128 "Trinity" to show it's a big tube..(but only 7.5kg in weight as shown)..

Close up view of the heavy duty clamshell which is over 2" wide..making it very easy to loosen and tighten up for easy adjustments.

View of the Tak EM2s head, showing the pair of hex bolt threaded holes at 35mm centres, ready to secure the clamshell (and OTA) to the mount.

The clamshell in situ looks quite small vs the almost 150mm diameter tube, but in practice holds the tube like a vice, but with only one component to loosen or tighten when making adjustments.

..and no problems when holding heavy loads👍

Dave

9 hours ago, Sunshine said:

Jeremy is smart, he waits for word from the scouts 😂

That's SGL speak, loosely translated in normal parlance as  "he's a tight old...." (insert your preferred adjective😉☺️😂)

Dave

2 hours ago, DirkSteele said:

Just doing my bit to crash the transfer of the forum to a new host in about 5 years! 😉

 

Delivery from FLO today. An Oklop bag - the 150/1200 refractor bag though I intend to use it with my LZOS 130/1200 and another book which perhaps I can add to the show us your Astronomy library thread.

I have the exact same holdall for my FS128..a great quality bag and my Tak fits it perfectly 👍😊.

Dave

Glad that's of some help, John😊

The ring adapter and the tool for removing/tightening/loosening various adapters were readily sourced from Flo. I'm sure they are also available elsewhere too..

Dave

Hi all,

The Baader T2 connectivity system is known for offering the greatest possible choices for connecting various astro accessories, and although not cheap, they offer excellent quality and build characteristics.

With the above in mind, I just wanted to share a useful small Baader accessory that I came across,  for increasing the versatility of my excellent Baader Zeiss BBHS T2 prism.

These days, I split my viewing between Binoviewing and Cyclops modes: for binoviewing I use 1.25" fit eyepieces, but for Cyclops I tend to use larger 2" eyepieces (some are 1.25" EPs fitted with 2" sleeves).

I have just the one Baader Zeiss prism which is physically the smaller sized unit, very similar as a bare bones prism to the standard T2 unit. 

I wanted to use my 2" and 1.25" clicklocks with the BBHS prism, and with the shortest light path..my 2" clicklock is the basic clicklock body, so I needed a short adapter to join the prism's T2 male thread to both 2" and 1.25" Clicklock's M48 female threads..and, I found this adapter with just 2.5mm optical length..

Some more photos follow, showing how I configure my BBHS prism in both 2" and 1.25" formats:

Hope that's of some help to others on here..😊

Dave

I've really liked decent quality orthos for years, for specific observing applications..

I would summarise the main pros and cons like this:

Pros:

- excellent for planets, lunar and double star observing

- simple design, with few inherent design aberrations

- good contrast and sharpness

- good (accurate) colour rendition

- premium brands (Tak, Baader, TMB) have good light transmission. In particular Baaders' Phantom coatings on their Baader Genuine orthos and Classic orthos are excellent.

- can deliver wonderful high power views in good conditions 

Cons:

- Narrow field of view, typically 40-46 degrees, so not ideal for Dobs or Altaz mounts at high power

- short eye relief on anything of c7mm or less. This becomes more problematic with age.

- not ideal for extended objects eg M42, M31 or star clusters and wide double/multiple star systems

- prone to showing floaters at high powers with increasing age

- probably best for F8 or slower scopes for Cyclops use, if you want the higher powers that orthos do best

Additional thoughts:

- I use an equatorial mount driven in R.A. only, with manual adjustment for the Declination axis. With just a line of sight alignment with Polaris ( I have a Polar axis finder but don't often use it) I can keep an object at high powers, say 150-200x in view for a good 30-40 minutes. 

I do appreciate that this is more difficult with an undriven Altaz or DOB mount.

- To help with short eye relief, I now use a pair of Tak Abbe 12.5mm for binoviewing. These have all the positive attributes mentioned above, and better eye relief than shorter focal lengths...by using them with a 2x or 2.25x Barlow, I can convert them to a 6.25mm or 5.5mm focal length to give higher powers, while maintaining acceptable eye relief..oh, and I use winged eyeguards which really help to control stray light and add comfort, for me at least.

- Floaters definitely seem less troublesome when orthos are used in pairs in a binoviewer..not exactly sure why, but perhaps two eyes help the brain to better relax and combine the best of both our eyes?

I really enjoy Double Star splitting with orthos, probably above all other uses👍😊

Dave

Hi Iain

The MBIIs and their T2 system allow me to use up to c35mm eyepieces with little or no vignetting with my MBIIs and Baader Zeiss BBHS prism which has a 34mm clear aperture..

..but even the standard T2 prism has 32mm clear aperture, and, with the MBIIs it's often possible to use binoviewing eyepieces natively, ie without the need for an OCS or Barlow lens.

I definitely consider the new Maxbrights to be one of my best ever astro investments👍😊.

Dave

8 hours ago, badhex said:

I haven't really had any opportunity to do observing in the last six months what with moving countries, but hopefully things are starting to settle down a bit so these will definitely be on the list of things to play with. 

I know what you mean.. January had a few good nights, but the next 3 months or so in the East of England were dire.

And the past couple of months have been full of family related stuff, visits, being visited, and clear sunny days with cloudy nights, combined with little real darkness..

The good news is that astro darkness begins to come back noticeably from August..👍😊

Dave